Bonding plastic floor pieces together

ABSTRACT

A method of bonding plastic floor pieces together includes several steps. One step involves laying plastic floor pieces near each other in order to produce a seam between neighboring plastic floor pieces. Another step involves cutting a groove into and along a part or more of the seam. Yet another step involves filling the groove with a bonding compound that can be composed of, among other constituents, methyl methacrylate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 61/915,131, the entire contents of which are herebyincorporated by reference.

TECHNICAL FIELD

The present disclosure generally relates to floor constructions, andmore particularly relates to ways of joining plastic floor piecestogether.

BACKGROUND

Because of their general durability, plastic floor pieces are commonlyused in areas and rooms that undergo an unusually high degree of wearand tear such as in building entrances, gymnasium weight rooms, lockerrooms, commercial kitchens, basements, livestock trailers, and patios.Plastic floor pieces are also used because they present softer walkingand running surfaces, and hence are easier on a person's joints. Whenlaid down side-by-side on a sub-floor or underlayment duringinstallation, a seam is produced at edges between neighboring andtouching floor pieces. To join the plastic floor pieces together, in thepast an installer performed a heat welding procedure. First, a groovewas formed at the seam and then a heat gun melted a plastic rod to putthe rod's material in the groove. Additional finishing steps may havealso been performed.

While this procedure made an acceptable joint between plastic floorpieces, the strength and quality of the joint oftentimes dependedlargely on the skill of the installer performing the heat weld. Forinstance, a poorly skilled installer could make a poor quality and weakjoint. Also, the heat welding procedure normally took more time thaninstallers would have liked—typically one-and-a-half to two linear feetalong the seam per minute.

SUMMARY

In one embodiment, a method of bonding plastic floor pieces togetherincludes the step of laying plastic floor pieces adjacent each other toproduce a seam between the plastic floor pieces. Another step involvescutting a groove into and along a part or more of the seam. And yetanother step involves filling the groove with a bonding compound thatcomprises methyl methacrylate.

In another embodiment, a method of bonding plastic floor pieces togetherincludes several steps. One step involves laying plastic floor piecesnear each other in order to produce a seam between neighboring plasticfloor pieces. Another step involves cutting a groove into and along partor more of the seam. The groove is cut part way into the seam in adirection generally orthogonal with top surface planes of the plasticfloor pieces. An extent of the seam remains uncut. Yet another stepinvolves dispensing a bonding compound into the groove. The bondingcompound is composed of, among other constituents, a resin part withmethyl methacrylate and an activator part. The resin and activator partsmix together as the bonding compound is in the midst of being dispensedinto the groove. The bonding compound is also dispensed into the uncutextent of the seam.

In yet another embodiment, a method of bonding plastic floor piecestogether includes several steps. One step involves laying plastic floorpieces near each other in order to produce a seam between neighboringplastic floor pieces. Another step involves providing a groove alongpart or more of the seam. The groove is provided part way into the seamin a direction generally orthogonal with top surface planes of theplastic floor pieces. An extent of the seam remains without a groove.Yet another step involves using a dispenser gun to dispense a bondingcompound into the groove and into the extent of the seam that remainswithout a groove. The dispenser gun has a first cartridge and a secondcartridge. The bonding compound is composed of a resin part and anactivator part. The resin part is held in the first cartridge and theactivator part is held in the second cartridge. The resin and activatorparts mix together as the bonding compound is in the midst of beingdispensed into the groove and into the extent of the seam that remainswithout a groove. And yet another step involves allowing the bondingcompound to cure in the groove and in the extent of the seam thatremains without a groove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a room with a floor constructionincluding plastic floor pieces;

FIG. 2 is an enlarged view taken at the circle denoted by numeral 2 inFIG. 1, showing a groove being cut into a seam of neighboring plasticfloor pieces;

FIG. 3 is an enlarged view of the groove being filled with a bondingcompound;

FIG. 4 is a sectional view of the bonding compound after it is filled inthe groove;

FIG. 5 is an enlarged view showing a protruding portion being removedfrom the bonding compound after the bonding compound is cured; and

FIG. 6 is a sectional view of the bonding compound and plastic floorpieces after the protruding portion is removed.

DETAILED DESCRIPTION

The figures depict steps performed in one example of a method of bondingplastic floor pieces together. The method uses a bonding compound thatcan be applied by a dispenser gun, instead of the heat gun and heatwelding procedure previously known. The bonding method can be easier toperform in many ways compared to the heat welding procedure, and makes amore consistently strong and high quality joint between plastic floorpieces than the previous procedure. Because it can be more readilyperformed, the bonding method depends less on the skill of the installerdoing the work. Also, compared to the heat welding procedure, installerscan make a joint using the bonding method much quicker—for example,typically about twenty-one linear feet per minute.

Referring now particularly to FIG. 1, a plastic flooring assembly 10 canbe installed in areas and rooms R that undergo an unusually high degreeof wear and tear, such as in a building entrance, a gymnasium weightroom, a locker room, a commercial kitchen, a residential basement, apatio, as well as in other areas and rooms. Other reasons for installingthe plastic flooring assembly 10 include its relative softness andaccompanying ease on a person's joints. The plastic flooring assembly 10is made up of numerous individual and initially discrete plastic floorpieces that are subsequently joined together. In the example of FIG. 1,a first plastic floor piece 12 is ultimately joined to a second plasticfloor piece 14. The phrase “floor piece(s)” is used broadly herein as agenus phrase for floor sheets, tiles, mats, coverings, and other similarfloor items. The plastic floor pieces 12, 14 are usually made of thesame plastic material, though need not be, and can be made out ofvarious kinds of plastic materials including, but not limited to, athermoplastic material, a vinyl material, or a polyvinyl chloride (PVC)material. Still further, the plastic floor pieces 12, 14 could includean embedded fiber reinforcement or some other reinforcement to augmentits strength and durability. One specific example of a floor piece thatcan be used in the bonding method detailed in this description are floorpieces sold under the product name PROTECT-ALL® by Oscoda Plastics,Inc., the original assignee of this patent. And the plastic floor pieces12, 14 can have different shapes and sizes, but are perhaps mostcommonly provided as rectangles and squares with a size of approximately5 feet by (×) 8 feet.

As mentioned, the method of bonding the plastic floor pieces 12, 14together detailed in this description makes a strong and high qualityjoint more consistently than previously known, and at a quicker pace.The method can include different steps in different examples. Indeed,the exact steps performed in a particular example may depend upon—amongother considerations—the material used for the floor pieces, the sizeand thickness of the floor pieces, and the composition of the bondingcompound used. Moreover, though described below with certain steps in acertain order, other examples of the bonding method could include more,less, and different steps, and the steps described could be performed ina different order.

In the example of the figures, the method of bonding the plastic floorpieces 12, 14 together includes several steps: laying the plastic floorpieces down, cutting a groove at a seam of the floor pieces, masking thesides of the groove, filling the groove with a bonding compound,smoothing out the bonding compound, pulling the masking off, allowingthe bonding compound to cure, and removing any protruding portion of thecured bonding compound. Again, not all of these steps need to be carriedout. For instance, the masking can be omitted in some examples.

Referring to FIGS. 1 and 2, in an initial step, the first and secondplastic floor pieces 12, 14 are laid down next to each other (in FIG. 1in particular, a third plastic floor piece 15 is shown in the midst ofbeing laid down). Their side edges 16, 18 produce a seam 20 between thefirst and second plastic floor pieces 12, 14 that runs vertically frombottom surfaces 22, 24 upward to top surfaces 26, 28 of the floorpieces. The seam 20 is produced by the confronting and in some casesabutting side edges 16, 18. The first and second plastic floor pieces12, 14 are depicted as set on top of a sub-floor 30, though this may notalways be the case. In other examples there could be an underlaymentinstead of, or in addition to, the sub-floor 30.

Referring now particularly to FIG. 2, in this example once the plasticfloor pieces 12, 14 are in place, a groove 32 is cut into and along apart or more of the seam 20. The groove 32 is cut into both of theplastic floor pieces 12, 14. The groove 32 can be cut in different ways.The cutting could be performed with a piece of equipment like a powergroover or a router P as depicted in the figure, or could be performedmanually by an installer's hand and a utility knife or straight edge;still, other ways of cutting are possible. However cut, the groove 32could have different shapes in cross-sectional profile including aU-shape as shown, a V-shape, a square, a rectangle, or a half-circle. Ithas been found that a U-shape in particular contributes to providing aconsistently strong joint. In general, the strength of a joint could bedetermined by conducting what-is-known-in-the-industry as a pull test inwhich a test plate or some other component is secured to floor pieces ator near the joint, and a force is exerted to pull up on the floor piecesaway from the sub-floor beneath the floor pieces; of course, othertechniques for checking joint strength are possible. A depth D of thegroove 32 measured from the top surfaces 26, 28 down to the groove'sbottom or lowermost point may vary in different examples depending on,among other considerations, the overall thickness of the first andsecond plastic floor pieces 12, 14 and the desired strength of theresulting joint. In one specific example, the groove's depth D isapproximately three-fourths (75%) of the overall thickness of the firstand second plastic floor pieces 12, 14. The three-fourths depth D hasbeen found to result in a consistently strong joint, but of course otherdepth values are possible. In another specific example, the groove'sdepth D is approximately three-sixteenth of an inch. In the example ofthe figures, and perhaps best shown by FIG. 4, an extent 34 of the seam20 remains uncut. Furthermore, in another example, the groove 32 couldbe cut before the plastic floor pieces 12, 14 are laid down—here,one-half of the groove 32 would be cut in separate procedures in each ofthe side edges 16, 18 of the plastic floor pieces. Still, the groove 32could be provided in other ways apart from cutting.

Referring now to FIG. 3, in the next step in this example, masking canbe carried out such as by applying adhesive tape 36 to the top surfaces26, 28 and on both sides of the groove 32. The adhesive tape 36 isoptional and need not be applied in all cases. The adhesive tape 36 isapplied in order to mask the top surfaces 26, 28 against inadvertent andunwanted contact with bonding compound in the next step.

After masking (if indeed carried out), the groove 32 is filled with abonding compound 38. The bonding compound 38, after it is completelycured, produces a bonded joint between the first and second plasticfloor pieces 12, 14. In this example the bonding compound 38 is a methylmethacrylate-based composition. Initially, and before the bondingcompound 38 is set into the groove 32, the bonding compound includes twodiscrete and separate parts that are mixed together as the groove isfilled. The parts then chemically react and cure in the groove 32 toultimately produce the bonded joint. In FIG. 3, a resin part 40 istemporarily held in one cartridge 42 of a dispenser gun 44, and anactivator part 46 is temporarily held in another cartridge 48 of thedispenser gun. The dispenser gun 44 can be manually-operated,battery-operated, or can be another type of gun. Once the gun isactuated, the resin part 40 and activator part 46 are pressed out oftheir respective cartridges and flow into applicator tips or nozzles 50,52 where, upon ejection, the resin and activator parts come together andmix as they are filled into the groove 32. The filling produces a streamor bead of bonding compound 38, as depicted in FIG. 3. The resin andactivator parts 40, 46 may be mixed in a 10:1 ratio, or at anothermixing ratio. Or, the mixing could occur within the dispenser gun 44, orwithin an applicator tip or nozzle. Of course, other ways of dispensingand mixing the resin and activator parts 40, 46 are possible, includingways that do not necessarily involve a dispenser gun. These steps can beperformed at room temperature and without the application of heat.

In one specific example, the resin part 40 is composed of approximately40-85 concentration percentage of methyl methacrylate, 1-10concentration percentage of methacrylic acid, and 5-15 concentrationpercentage of 2-chloro-1,3 butadiene. And the activator part 46 iscomposed of approximately 10-40 concentration percentage of benzoylperoxide, 10-30 concentration percentage of bisphenol A diglycidyl etherresin, 10-30 concentration percentage of dibutyl phthalate, and 1-10concentration percentage of other non-hazardous ingredients. Resin andactivator parts like these can be supplied by ASI Adhesive Systems, Inc.with an office at 9411 Corsair Road, Frankfort, Ill. 60423, U.S.A. Inaddition to the groove 32, the bonding compound 38 can also be filledand inserted into the uncut extent 34 of the seam 20 if a space isdefined at the uncut extent by confronting side edges 16, 18. When theuncut extent 34 is filled, the bonded joint between the plastic floorpieces 12, 14 can be enhanced compared to a joint with only its groovefilled with bonding compound.

In the specific example set forth above, the bonded joint is heldtogether by more than a mere adhesion via adhesive, and instead is heldtogether via a chemical weld. The chemical weld intermixes the materialsof the first and second plastic floor pieces 12, 14 with the compositionof the bonding compound 38, and chemically fuses the plastic floorpieces together at the seam 20.

As described, the bonded joint has a more consistently strong and highquality hold between the plastic floor pieces 12, 14 because the bondingcompound 38 can be more readily filled in the groove 32 than theprevious heat welding procedure. That is, comparatively less skill isneeded to fill the groove 32 with the bonding compound 38 than thatneeded for a proper heat weld. This can be by way of the dispenser gun44, or by another technique. Previous heat welds can also exhibitstrength and quality discrepancies among different welds as a result ofthe needed skills and different installer abilities, whereas it has beenobserved that the bonded joints of bonding compound 38 exhibit little orno discrepancies among different welds and among different installers.Indeed, in one specific observation, different bonded joints enduredpull test forces of up to approximately 1,150 pounds. This result isconsidered acceptable according to industry standards.

Shortly after the groove 32 is filled with the bonding compound 38, andbefore the bonding compound is completely cured, the installer mayflatten and smooth out an exposed surface 54 (FIG. 4) of the bondingcompound. This action can help ensure that the groove 32 is fully filledwith the bonding compound 38, and the action might also urge the bondingcompound into the uncut extent 34 of the seam 20, if an uncut extent ispresent and intended to be filled. The flattening and smoothing can becarried out via a putty knife or some other tool.

If the masking was carried out in an earlier step, the masking could nowbe taken away by the installer or at a later time such as when thebonding compound 38 is allowed to completely cure and harden. In thecase of the adhesive tape 36, the adhesive tape could be pulled off ofthe top surfaces 26, 28. The curing may occur at room temperature andwithout external accelerants or facilitators like heat. The exact curingduration will depend on the exact composition of the bonding compound38. In the specific example set forth above with the resin and activatorparts 40, 46, for instance, an initial and non-final cure time is up toapproximately three to five minutes and a final cure time isapproximately thirty minutes. Still, some typical cure times have beenshown to be approximately ten minutes.

And as a possible last step, and referring now to FIG. 5, the installercan remove a portion 56 of the bonding compound 38 projecting andbulging above the top surfaces 26, 28 of the plastic floor pierces 12,14. The portion 56 is also denoted in FIG. 4 by the portion locatedabove the broken line in the figure. This action can be carried out viaa skiving knife S and blade B, or some other tool or technique. Theinstaller can remove the protruding portion 56 after final curing, orafter an initial and non-final cure when the bonding compound 38 issemi-hardened. Whenever performed, the finished bonded joint as depictedin FIG. 6 has its exposed surface 54 substantially flush withinworkmanship precision and tolerances with the top surfaces 26, 28 of theplastic floor pieces 12, 14. Furthermore, in another example, theportion 56 need not be removed or simply may not be present.

The foregoing description is considered illustrative only. Theterminology that is used is intended to be in the nature of words ofdescription rather than of limitation. Many modifications and variationswill readily occur to those skilled in the art in view of thedescription. Thus, the foregoing description is not intended to limitthe invention to the embodiments described above. Accordingly the scopeof the invention as defined by the appended claims.

What is claimed is:
 1. A method of bonding plastic floor piecestogether, comprising: laying plastic floor pieces adjacent each other toproduce a seam between the plastic floor pieces; cutting a groove intoand along at least a part of the seam; and filling the groove with abonding compound comprising methyl methacrylate.
 2. The method of claim1, further comprising applying tape on top surfaces of the plastic floorpieces and at both sides of the groove before filling the groove withthe bonding compound.
 3. The method of claim 1, further comprisingsmoothing out an exposed surface of the bonding compound once thebonding compound is filled in the groove and before the bonding compoundis cured.
 4. The method of claim 1, further comprising removing aportion of the bonding compound protruding above top surfaces of theplastic floor pieces once the bonding compound is at least partly cured,wherein an exposed surface of the bonding compound after removal issubstantially flush with the top surfaces of the plastic floor pieces.5. The method of claim 1, further comprising allowing the bondingcompound to cure in the groove.
 6. The method of claim 1, whereincutting the groove comprises cutting the groove via a power groover. 7.The method of claim 1, wherein the groove is cut part way into the seamin a direction generally orthogonal with top surface planes of theplastic floor pieces, leaving an extent of the seam uncut, and thebonding compound is filled in the uncut extent of the seam before thebonding compound is cured.
 8. The method of claim 7, wherein the groovehas a depth that measures approximately three-fourths of the overallthickness of the plastic floor pieces at the seam, and the uncut extentof the seam constitutes the remaining extent of the groove.
 9. Themethod of claim 1, wherein the groove cut into and along at least partof the seam is a U-shaped groove.
 10. The method of claim 1, whereinfilling the groove comprises dispensing the bonding compound in thegroove via a dispenser gun.
 11. The method of claim 10, wherein thedispenser gun has a pair of cartridges and the bonding compoundcomprises a resin part with the methyl methacrylate and an activatorpart, the resin part being held in one of the pair of cartridges and theactivator part being held in the other of the cartridges, the resin partand the activator part mixing together as the bonding compound is beingdispensed in the groove.
 12. The method of claim 1, wherein the plasticfloor pieces are polyvinyl chloride (PVC) sheets.
 13. The method ofclaim 1, wherein the bonding compound forms a chemical weld comprisingintermixed materials of the plastic floor pieces.
 14. A method ofbonding plastic floor pieces together, comprising: laying plastic floorpieces adjacent each other to produce a seam between the plastic floorpieces; cutting a groove into and along at least part of the seam,wherein the groove is cut part way into the seam in a directiongenerally orthogonal with top surface planes of the plastic floorpieces, leaving an extent of the seam uncut; and dispensing a bondingcompound into the groove, the bonding compound comprising a resin partwith methyl methacrylate and an activator part, the resin and activatorparts mixing together as the bonding compound is being dispensed intothe groove, the bonding compound dispensed into the uncut extent of theseam.
 15. The method of claim 14, wherein dispensing the bondingcompound is performed via a dispenser gun, the dispenser gun having afirst cartridge and a second cartridge, the resin part held in the firstcartridge and the activator part held in the second cartridge.
 16. Amethod of bonding plastic floor pieces together, comprising: layingplastic floor pieces adjacent each other to produce a seam between theplastic floor pieces; providing a groove along at least a part of theseam, wherein the groove is provided part way into the seam in adirection generally orthogonal with top surface planes of the plasticfloor pieces, leaving an extent of the seam without a groove; using adispenser gun to dispense a bonding compound into the groove and intothe extent of the seam without a groove, the dispenser gun having afirst cartridge and a second cartridge, the bonding compound comprisinga resin part and an activator part, the resin part held in the firstcartridge and the activator part held in the second cartridge, the resinand activator parts mixing together as the bonding compound is beingdispensed into the groove and into the extent of the seam without agroove; and allowing the bonding compound to cure in the groove and inthe extent of the seam without a groove.